You need to complete the testing of individual features and all the areas need to be stable to truly start end-to-end testing. In reality, you end up making some exceptions sometimes, but this is not ideal. Pick a selected core group for end-to-end testing. Everyone involved needs to know the end-to-end business flow. Usually, the finance team has a bigger role to play here, as they have a visibility into all the parts of the organization.

Plan for at least two rounds of end-to-end testing, with some time in between to fix the bugs. Define the exit and success criteria prior to getting into end-to-end testing (such as 100 percent test execution, more than a 95 percent pass rate, and no more than five critical bugs open).